Support for sound projecting apparatus



Sept. V3o, 1947. w.. EM/Es 2,428,270

SUPPORT FOR SOUND PROJECTING APPARATUS Filed April 25, 1944 5 sheeis-snet 1 INVENTOA fwn-"vw ff' mam' JM- f0.7 40,2 v Arrivi/v51 Sept. 30, 1947. w. c. EAvEs i 2,428,270

SUPPORT FOR SOUND PROJECTING APPARAEIIIS' Filed April 25, 1944 5 sheets-sheet-z W IIIII HIIIIIIIWI'IIIII n w j w www 1 imm sept.3o,1947. cfm/Es. I '2,428,270'-.

SUPPORT FOR SOUND PROJEGTING APPARATUS- Filed April 25, 1944 sfsheeis-sn'eet 5 INVENTOK Sept. 30, 1947.

W. C. EAVES SUPPORT FOR SOUND PROJECTING APPARATUS Filed April 2'5, 1944 5 Sheets-Sheet 4 Sept. 30, 1947. W, C, EAVES 2,428,270

SUPPQRT FOR SOUND PROJECTIIQNG APPARATUS l i Filed April 25, 1944 I Sweets-sheet 5 v Patented Sept. 30, 1947 SUPPORT FOR SOUND PRJECTING APPARATUS William C. Eaves, Elyria, Ohio, assigner to Eaves Sound Projectors, Inc., Dover, Del., a corporation of Delaware Application April 25, 1944, Serial No. 532,620'

This invention relates to sound amplifying apparatus and more particularly to mountings for horns or trumpets that are associated with such apparatus.

An object of the present invention is to provide novel supporting and directionalv control means for a horn whereby the latter may be controlled from a remote poi-nt to direct the sound emanating therefrom in a desired direction.

Another object is to provide a horn mount embodying novel supporting and control means whereby the horn may be located at a high elevation and rotated about vertical and horizontal aires from a remote Vpoint to variousv positions, and locked in any of said positions.

Afurther object is to provide mechanism operable from a. remote point for rotating a sound amplier' in opposite directions in two planes to variouspositions, in combination with novel means at said point for indicating the direction of rotation of said amplifier and the4 position occupied by the latter.

The above and further objects and novel feaof the present invention will more fully appear from the following detailed` description when the'same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended asa denition of the limits of the invention, reference for this latter purpose being had primarily to the appended claims.

In the drawings, wherein like reference char-l acters refer to likerparts throughout the several views,

Fig. 1 is a side elevation of a horn, and supportingy and directional control means therefor embodying the present invention, with portions ofsaid means broken away for purposes of clearer illustration;

Fig. 2v is an enlarged fragmentary end View, partly in section, of the horn and supporting means therefor illustrated in Fig. 1 and looking from the left of said gure;

Fig. 3' is an enlarged vertical transverse sectional view of the lower end portion of the horn supporting and directional control means, illustrated in' Fig. 1 and lookingv from the right of the latter figure; Y

Fig. 4 is an enlarged vertical longitudinal sectional view of the upper end portion of the horn supporting means illustrated in Fig. 1;

Fig.5 is a horizontal sectional View on the line 5-5 of-Figfl; Y* i Fig. 6 is a fragmentary side elevation, lookingV 10 Claims. (Cl. 248-183) 2 from the right of Fig. 3, of the horn directional control and locking means;

Fig. is an enlarged fragmentary top plan View of the horn and the mounting members at one side tlfie'reof;

Fig. 8 is an enlargedA horizontal sectional view taken on the line -f-S of Fig. 6;

Fig. 9 is a fragmentary side elevation of the horn and its supporting means, with portions broken away, showing quadrant means associated therewith and forming part of the directional control means;

Fig. i0 is an enlarged fragmentary end View, looking from the left of Fig. 9", showing the quad' rant and one of the mounting members therefor;

Fig, 1I is an enlarged fragmentary end view, looking from the left of' Fig. 9, showing the other ofthe mounting members for the quadrant;

Fig. 1-2 is an enlarged vertical transverse sectional view of the quadrant taken at a point ap'' proximately midway between the ends thereof Fig. i3 is an enlargedA top plan View, partly in' section, of the horn' supporting means, and the quadrant means, illustrated in Fig. 9; with parts' omitted for purposes of clearer illustration;

Fig. I'4 isV an enlarged horizontal section of drectional' indicating. means embodying the present invention and' illustrated in Figs. l andY 6;

Fig. 15 is a .section on line lil-I 5v of Fig. 14'; and

Fig. I6' i's a front elevation. of. said indicating means The novelhorn supporting and directional control means of the present invention is particularly adapted for use with pneumatic sound projecting apparatus installed at airports, military and naval bases, ships, etc., for transmitting orders-ins ructions, or sound signals to airplanes, and tothe personnel ci said bases and ships. Accordinglmthe is herein illustrated as befing mounted on a support 25 (Fig. 1) such as, for example, the deck of a ship, or the roof or' platform of a control station; at. an airport.

As shown, the horn: is rotatably supported by means of a novel construction` comprising a long tubular mast 26 GFigs. l, 3- and 4) havingwelded. or otherwise suitably secured to the lower end thereof a; relatively' large. base flange 2'1 which, in turn. is secured, as by bolts 28', to the upper surface of support 25. Positioned within mast 26 is a tube 29: which is of a length such that the opposite ends thereof project beyond the opposite ends.v of. said mast, the support 25 being provided with a suitable opening 30` to receive the'lower projecting end. fsaid tube. The outer diameter of tube 29 is materially less than the inner diameter of the mast.

Surrounding mast 26 and secured thereto near the upper end, as by bolts 3i, is a anged collar 32 (Figs. 1 and 4) adapted to support two vertically spaced roller bearings 33 and 34 which also surround the mast and are held in spaced relation by a sleeve 35. Bolts 3l are threaded through collar 32 and are formed with reduced end portions 36 that engage in suitable openings in the mast to firmly secure said collar to said mast. Bearings 33 and 34 rotatably support and guide a cylindrical housing 31 concentric with mast 26. At its upper end, housing 31 is secured to the upper projecting portion of tube 29, as by bolts 38, and extends downwardly therefrom and over bearings 33, 34 and the flange of collar 32. Bolts 38 are threaded through housing 31 and formed with reduced end portions 39 (Fig. 5)` engaged in suitable openings in tube 29 to ilrmly secure said housing to said tube and against relative rotation. Tube 29 is thus rotatably supported by mast 26 through the above described housing 31, bearings 33, 34 and iianged collar 32. Housing 31 and tube 29 are held against upward displacement by a retaining ring 40 which is secured to the lower end of said housing, as by set screws 4l, and provided within an inturned ange 42 that v is disposed beneath the flange of collar 32. Ring 46 is assembled on mast 26 at the time collar 32 is engaged over said mast, the ange 42 of said ring being provided with an enlarged central Opening 43 to permit the hub portion of collar 32 to extend therethrough.

Rigidly secured to the upper end of tube 29 above housing 31 is a yoke 44 (Figs. 1, 2 and 4) having a pair of transversely spaced, vertically and rearwardly extending arms 45 adapted to receive therebetween, and support, a trumpet or horn indicated generally at 46. Horn 46 may be of any suitable size or type, and is herein shown, for purposes of illustration only, as a multiple unit horn of the type illustrated and described in my copending application Serial No. 517,628, led January 10, 1944. As illustrated, the horn comprises eight interconnected rst and second throat sections 41 and 48 which are disposed in spaced parallel relation, and are bolted to a common junction body 49 having a bell 50.

In order to facilitate adjustment of the horn to a selected position in azimuth and elevation. means are provided for balancing the horn on arms 45 of the yoke. As shown, horn 46 has engaged over its throat sections 46 a circular plate I (Figs. 1, 2, 7 and 9) which is clamped to said sections adjacent the rear ends thereof by two-l part clampsv 52 secured to said plate. Welded or otherwise suitably securedto plate 5I are two diametrically disposed angle brackets 53 (Figs. 2 and 7) which extend rearwardly through said plate and have secured thereto, as by bolts 54, corresponding ends of oppositely disposed arms 55. Arms 55 extend from brackets 53 forwardly along opposite sides of horn 46 and have their corresponding opposite ends secured as by bolts 56, to the junction body 49 of said horn. Y

Horn 46 is positioned between arms 45 of yoke 44 and is pivotally mounted on said arms by studs 51( Fig. 7) which are journalled in suitable bearings in the upper ends of the arms 45. Each stud has a reduced portion 5 8 that is threaded in a suitable opening 59 in arm 55. Openings 59 in arms 55 are so located that the portions of horn 46 `extending. forwardly and rearwardly of the pivot 51=wil1 counterbalance each other. A bowed housing 1 I.

.4 spring washer 60 (Fig. '1) is inserted between the heads 6i of studs 51 and the adjacent surfaces of arms 45 to provide a frictional drag on the studs.

Novel means are provided for rotating tube 29 from a remote point whereby horn 46 may be conveniently moved in azimuth to any selected position, and the amplied sound may be propagated in a desired direction. As herein shown, said means preferably comprise a tube 62 (Figs. 1 and 3) having the same outside and inside diameters as tube 29, and which is connected with the latter through the medium of a coupling 63, thus forming an extension of tube 29. Coupling 63 is welded or otherwise suitably secured to the upper end of tube 62 and provided with an internally threaded portion 64 having threaded engagement with the lower threaded end of tube 29. To further secure tube 62 to tube 29 and prevent relative rotation of said tubes, coupling 63 is provided with one or more set screws '65 engaged with tube 29.

Tube 62' extends downwardly through the opening 39 in support 25, and is journalled in a suitable bearing in a bracket 66 (Figs. 1, 3 and 6) secured, as by bolts 61, to the underside of said support. Bracket 66 is preferably made in two parts to facilitate assembling of said bracket to tube 62, and removal of the same for repair or replacement purposes, the two parts of said bracket being bolted together by bolts 63. Tube 62 extends downardly to a convenient operating point, and is rotated by a hand-wheel 69 which may be secured directly to the lower end of said tube, but, as herein shown, is preferably secured, as by bolts 10, to a housing 1I to be hereinafter described, said housing being secured, in turn, as by bolts 12, to the lower end of tube 62. Bolts 12 are threaded through the upper reduced portion of housing 1i and formed with reduced end portions13 which engage in suitable openings in tube 62 to prevent rotation of said housing relative to said tube. By rotating hand wheel 69, tubes 62 and 29 will be rotated through housing 1i, thereby eiecting rotation of horn 46 about a Vertical axis.

Novel means are provided for locking horn 46 vin any selected positions in azimuth, and for limiting rotation of said horn about the vertical axis of its support to one revolution in opposite directions. As herein shown, said means preferably comprise a brake arm 14 (Figs. 6 and 8) pivoted on a stud 15 that is threaded in one side of the Pivotally connected at 16 with the arm 14 is oneend of a rod 11, the opposite end of which is pivotally connected at 18 with a dog 19. The latter is engaged in the forked upper end of an arm 89 and is pivoted intermediate the ends thereof on a stud 8| that is threaded in said arm. Arm 86 is formed integrally with a two-part bracket 82 that is clamped to tube 62 beneath bracket 66 as by bolts 83. When the dog is in the dotted line position of Fig. 6, rotation of tubes 62 and 29 by hand wheel 69 through housing 1I, will impart a like movement to brake arm 14, rod 11, dog 19 and bracket 82.

As shown in full lines in Figs. 3 and 6, dog 19 is adapted to project into the space between 'any from teeth 8'4 is effected by downward movement of arm 14 and rod 11.

Dog 19 is held 4in operative, or in disengaged positions by novel latch means comprising a pawl 65 (Fig. 8) which is `adapted to be engaged in one or the other of two notches 86 and 81 (Figs. 6 and 8) that are formed in an arcuate plate 06 which is secured to and spaced from the housing 1I by bolts 69 and spacers 9E). Pawl 66 is slidably mounted in a slot 9| formed in arm 14, and is yieldingly held against lateral movement relative to said arm by a disk 92 secured to said pawl by a screw 93. Connected with pawl 85 is one end of, rod 94 which extends through the hollow handle 95 of arm 14 and is provided on the opposite end thereof with a push button 96. Surrounding rod 94 and disposed within handle 95 and between the latter and the push button 96 is an expansion spring 91 for biasing the pawl 85 toward the plate 8S. Notches 66 and 81 determine the operative and disengaged positions, respectively, of dog 19, and upon disengagement of pawl 85 from said notches through depression of push button 96, dog 19 may be moved by arm 14 into and out of engagement with teeth 84 to lock the horn in a selected position in azimuth.

Rotation of horn 46 as hereinbefore described, is limited to substantially 360 in opposite directions. For this purpose, the teeth 64 on bracket 66 include a tooth 98 (Figs. 3 and 6) which projects beyond the teeth 84, and may extend the full length of said bracket. When dog 19 is raised and held out of engagement with teeth 84, tooth 96 will be in the path of rotation of the dog and will be engaged by the latter, thereby limiting rotation of horn 46.

With the construction thus far described, horn 46 may be adjusted to any position about a vertical axis to direct the sound emanating therefrom in a desired direction in azimuth. It is desirable,

' however, that horn 4,6 be capable of adjustment in elevation about a horizontal axis also, whereby the sound emanating therefrom may also be directed upwardly or downwardly, as desired. Accordingly, novel means are provided for tilting horn 46 on its supporting mast, said means being operable from the same convenient point at which horizontal rotation is imparted to said horn. As shown, there is journalled in suitable bearings in housing 1| and in hand wheel 69 a vertically disposed stub shaft |60 (Fig. 3) having xed thereon a worm l Disposed within hand wheel 69 and secured to the lower projecting end of shaft |66 is a hand wheel |62 preferably provided with a handle |63, for effecting rotation of shaft |60 and worm I6! in opposite directions. Worm I6! meshes with a worm wheel |64 which is fixed on a stub shaft |96 that extends transversely of housing 1| and is journaled in suitable bearings in said housing. Shaft |65 is disposed directly beneath tube 62 and has xed thereon a drum |06. The central portion of a flexible cable |61 is wound around drum |96, and they end portions |68 and |69 of the cable extend from the drum up through tubes 62 and 29 to the top of the latter and then pass over and around suitable grooved sheaves |16 and respectively (Fig. 9). Sheaves H6, project through suitable slotted openings in housing 91 and tube 29 and are journaled on pins l2 (Fig. 5) carried by said housing, From the sheaves l i6, I, the cable portions 68, 169 extend upwardly in opposite directions, then toward each other beneath horn 46, and have their free ends connected in a mannerto be described, to a quadrant |13. The lat- 6 ter is disposed between the arms 45 of yoke 44, and comprises a curved, inverted V-shapedmember ||4 providing a guide for cable portions |06, |09, and having a cross brace H5 and a center brace |-=|6 (Figs. `9 and 12), said braces `being welded together and to said member.

The quadrant is secured to horn 46 to rtransmit to the latter the movements of cable portions |68, |09, whereby tilting of said horn upwardly or downwardly on yoke 44 is effected. -Accordingly, member ||4 has welded to `one end thereof a vertical plate ||-1 (Fig. 10.) which is secured, as by bolts 118, to the lower end of plate 5|. Welded Ito the opposite 'end of member |.|'4 is L-shaped ^member H9 (Figs. 9 and 11) which extends upwardly between adjacent vthroat "sections 48, and `horizontally beneath horn 46, `and is secured to vsaid vsections and the bell of ksaid horn, as by bolts '|20 and 121, respectively.

Cable portion |08 extends from sheave |'|.0 upwardly along member H4, then horizontally beneath horn 46 through registering openings |122 (Fig. 10) formed in plates ||1 and 6|, Tand has its free Vend connected through the medium of a turnbuckle |23 with an anchor plate |24 which is welded to the cross brace I6 or" quadrant |.|3 (Figs, 9 and 12v). Cable portion |69 extends trom sheave upwardly along member ||'4, then horizontally beneath horn 46 through enlarged openings .|25 'and |26 (Figs. 11 and 13) formed in member H9, and .has its free end connected through the vmedium of a turnbuckle |21 with plate |24. 'Cable portion |63 is maintained taut and in engagement with quadrant ||3 by a grooved sheave |28 (Figs. 4, 9 and 13) journalled at |29 (Fig. 4) between a pair of arms |30 that are secured to opposite :ends of a pin |3| that is rotatably mounted in yoke 44 and tube 29. Connected to arms |30 are pull springs |32, the opposite ends of which are connected with a U- shaped bracket |33 that is welded or otherwise suitably secured to yoke 44 between arms 45.

Upon rotation of drum |06 in one direction through .the described driving means with hand wheel |62, the cable portion |08 will be wound upon vsaid drum, and the cable portion |69 will be unwoun'd therefrom, thereby shortening land lengthening said cable portions, respectively, rand rotating horn 46 through quadrant ||3 in a counter-clockwise direction as viewed in Fig. 1. When drum |06 is rotated in the opposite direction, vthe above-described winding and unwinding of :cable portions |68, |09 will be eiected in reverse order, and horn 46 will be rotated through quadrant ||3 `in a clockwise direction as viewed in Fig, `1. It will be noted that through association of the means for eiecting rotation of horn 46 about va horizontal axis with the means for effecting rotation of said horn about a vertical axis, adjustment of the horn upwardly or downwardly may be effected in all positions of horizontal adjustment.

Novel indicating means are provided to facilitate adjustment of the horn to a selected position in a vertical plane. As shown in Figs. 14 to 16, said indicating means comprises a spur pinion |34 which is secured, as by a screw |35, to one end of drum shaft |05 exteriorly of housing 1|. Pinion |34` meshes with a large spur gear |36 of a compound idler including a small spur gear |31. Gears |36, |31 are secured in a suitable manner to a stud |38 journalled in a bracket |39 secured to and spaced from the adjacent side lof Bracket 39 is providedwith an enlarged opening 7 |42 to receive the hub of pinion |34 and to provide sufficient clearance for rotation of said pinion. Gear |31 meshes with a considerably larger spur gear |43 journalled on a stud |44 secured in bracket |39. Pinion |34, and gears |36, |37 and |43 are enclosed in a casing |45 engaged over bracket |39 and secured -to housing Secured to gear |43, as by bolts |46, is a clip |4'| which extends through a suitable opening |48 in casing |45, and has secured thereto, as by bolts |49, an indicator hand |50. YHand |50 cooperates with a segmental dial |5| secured to casing |45, as by screws |52, said dial being graduated in tens of degrees in opposite directions frcm zero. Gears |34, |36, |31 and |43 are so proportioned that hand |50 will have a movement imparted thereto equal in degrees to the degrees of rotation of horn 46, in a vertical plane, and this gearing is so arranged that the direction of movement of hand |50 will correspond to the direction of movement of said horn. When the horn is in zero position hand |50 will read zero on dial |5|, adjustment of the hand being eiected by inserting a screw driver or similar tool through a suitable opening |53 in casing |45, loosening screw |35 to free pinion |34, and permitting rotation of hand |50 to proper position.

Adjustment of horn 46 in elevation to a desired position may thus be quickly and accurately accomplished by rotating hand Wheel I 62 and observing the direction of rotation o-f hand |56 relative to dial |5|, and movement of said hand to a desired position as indicated on said dial. To prevent damage to horn 46 through excess rotation thereof in opposite directions in elevation, spaced pins |54 are secured in casing |45 for engagement by clip |4'| and hand |55 when the safe limit of rotation of said horn in either direction is reached. The stop positions are also indicated on dial |5|.

The entire horn assembly may be steadied by guy wires (not shown) havingV corresponding ends thereof secured to support 25 and opposite ends secured to thimbles |55 (Figs. 1 and 9) carried by clamps |55 suitably attached to mast 26. Mast 23 may also be provided with vertically spaced steps |57 to enable ascending of the mast for purposes of repair or adjustment.

There is thus provided novel supporting and directional control means enabling location of a horn or other projector such as a light, at a high elevation, and rotation thereof from a remote point to a selected position in azimuth AandY elevation to direct the sound emanating therefrom. The present invention also embodies novel locking means for holding the horn in various positions of adjustment, and novel indicating means which eliminates all guessing on the part of the operator in adjusting said hornV in a vertical direction to a desired position. i

Although only a single embodiment of the invention has been illustrated and described in the foregoing ,specicatiom it is to be expressly understood that changes may be made therein particularly in the design and arrangement of the parts illustrated, without departing from the spirit and scope of the invention, as willY now be clear to those skilled in the art. For a denition of the limits of the invention, reference ishad primarily to the appended claims.

What is claimed is:

1. In apparatus of the class described, a support,v a horn, means secured to said support and extending upwardly therefrom for supporting said horn at an elevation, and means operable from a point beneath said support for rotating 'said horn relative to said support and said rstnamed means about vertical and horizontal axes to various positions to direct the sound emanating therefrom in a desired direction.

2. In apparatus of the class described, the combination of a xed tubular mast, a tube within said mast and rotatably supported thereby, said tube extending above and below said mast, means connected with the lower end of said tube for rotating the latter in opposite directions, means for releasably locking said tube in various positions of rotation thereof and for limiting rotation of the tube to substantially one revolution in said directions, said last named means comprising a iixed annular member having a plurality of teeth and including one tooth which extends radially and axially beyond the others,

a pivoted dog on said tube and rotatable therewith, an arm carried by said tube and connected with said dog for moving the latter into and out of engagement with said teeth, said dog upon disengagement thereof from the teeth being disposed in position to contact said tooth, and latch means for releasably holding said dog in engagement ,with and disengaged from said teeth.

3. In sound projecting apparatus, a support, a horn, means carried by said support and extending upwardly therefrom for supporting said horn atan elevation and for pivotal movement at said elevation about a horizontal axis, and means operable from a point beneath said support and connected with said horn for rotating the latter relative to said support and said first-named means about said axis to various positions.

4. In combination, a support, a horn, means carried by said support and extending upwardly therefrom for supporting said horn at an elevation and for pivotal movement at said elevation about a horizontal axis, means operable from a, point beneath said support and connected with said horn zfor rotating the latter relative to said support and said first-named means in opposite directions about said axis to various positions, and means at said point for indicating the direction of rotation imparted to said horn and movement of the latter to a desired position.

' 5. In apparatus of the class described, the combination of a projector supported for pivotal movement about a horizontal axis, a quadrant secured to said projector, a flexible elementhaving opposite ends connected with said quadrant, and means for operating said flexible element and said quadrant whereby rotation of said projector about said axis to various positions is eifected.

6. In sound projecting apparatus, the combination oi a vertically extending tubular support, a horn mounted. on said support at the upper end thereof for rotation about a horizontal axis, a quadrant carried by said horn, a flexib'le element extending through said support and having opposite ends'connected with said quadrant, and means at the lower end of said support and including a drum for operating'said flexible element and said quadrant whereby rotation of said Vhorn about said axis to various positions is effected.

7. In apparatus of the class described, the combination of a vertically extending tubular member, a horn mounted on said member at the upper end thereof for rotation about a horizontal axis, a quadrant secured to said horn, means for rotating said horn about said axis in opposite-directions to various positions and comprising a housing secured to the lower end of said tubular member, a drum rotatably mounted in said housing, a exible element wound around said drum and extending upwardly through said member and having opposite ends thereoin connected with said quadrant, and means for ndicating the direction of rotation imparted to said horn and the movement of the latter to a desired position, said indicating means comprising a dial secured to said housing, a hand cooperating with said dial, and gearing between said drum and said hand for operating the latter from the former in a manner such that the direction and extent of rotation of said hand and said horn are identical.

8. In apparatus of the class described, a support, a horn, means secured to said support and extending upwardly therefrom for supporting said horn at an elevation, means operable from a point beneath said support for rotating said horn about a vertical axis to various positions, separate means operable at said point for rotat ing said horn in opposite directions about a horizontal axis to various positions, and means at said point and responsive to the operation of said last-named means for indicating the direction of rotation imparted to said horn by said last named means and the movement of the horn to a desired position.

9. In sound projecting apparatus including a horn, the combination of a xed tubular mast, a tube within said mast and extending above and below the same, a yoke secured to the upper end of said tube for supporting said horn thereon, means forv rotatably supporting said tube 10 on said mast and including a housing xed on the tube and a pair of vertically spaced antifriction bearings on the mast and engaged by said housing, and means associated with the lower end of said tube for rotating the latter and the horn carried thereby.

10. In sound projecting apparatus of the type embodying a horn, the combination of a xed tubular mast, a tube within said mast and eX- tending above and below the same, a yoke secured to the upper end of said tube for supporting said horn thereon, means for rotatably supporting said tube on said mast and including a pair of vertically spaced anti-friction bearings on the mast and a housing fixed on the tube and engaged over said bearings, means holding said housing and said tube against upward endwise displacement relative to said mast, and means associated with the lower end of said tube for rotating the latter and the horn carried thereby.

WILLIAM C. EAVES.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,082,053' Tessier Dec. 23, 1913 1,276,220 Howell I Aug. 20, 1918 1,686,904 Ely oct. 9, 1928 1,754,520 Marsh Apr. 15, 1930 2,166,394 Crossley July 13, 1939 1,270,355 Wright June 25, 1918 

